Alkylation of hydrocarbons



Patented Apr. 11, iii-t4 2,346,452 summon ornrnnocaanons Ernest F. Pevere, Beacon, Louis 3. Clarke, Fishkiil, and George B. Hatch and Frank H. Brunet, Beacon, N. Y., assignors, by means to, to The Texas Company, New York, N. Y., a cor poration'of Delaware No Drawing. Application May 13, 1939, Serial No. 278,574

Claims. (CL Mil-683.4)

This invention relates to the manufacture of motorfuels and has to do particularly with the production of high anti-knock motor fuels, such as gasoline, by the reaction of isoparaflins, for ex- I ample, isobutane, with oxygenated hydrocarbon V compounds in the presence of an alkylation cata-. lyst, such as sulphuric acid. I

The invention broadly contemplates reacting iso with an oxygenated hydrocarbon, such as alcohols and etheis, in the presence of an alkylation catalyst, such as concentrated sulphuric In pending application, Serial No. 148,978,v on which Patent No. 2,260,945 has now issued on a divisional application thereof, alkylation of isoparailin hydrocarbons with olefin hydrocarbons in the presence of concentrated sulphuric acid is disclosed. This alkylation reaction results in the production of saturated gasoline hydrocarbons of hi h anti-knock value.

We have discovered that gasoline hydrocarbons of high anti-knock value may be prepared by reacting such as isobutane, with oxygenated hydrocarbons in the presence of concentrated sulphuric acid. These oxygenated hydrocarbons comprise aliphatic and hydroaromatic alcohols and aliphatic ethers.

While alcohols having less than about three carbon atoms in the molecule do not appear to alkylate satisfactorily under the usual conditions or temperature which can be employed without objectionable deterioration of sulphuric acid as a catalyst, we have found that aliphatic alcohols having from about three to ten carbon atoms are K particularly suitable for alkylation in the presence of sulphuric acid to produce a product within the guoline boiling range. Higher molecular weight alcohols may be allrylated also for the production of a product suitable as a safety fuel. Ethers corresponding to these alcohols, for example, butyl ether corresponding to normal butyl alcohol, isopropyl ether corresponding to isopropyl alcohol, etc, may likewise be alkylated.

' Somewhat diilerent conditions of alkylation are desirable for the different alcohols and ethers.

) In general, the primary alcohols require higher temperatures than the secondary and tertiary alcohols; and the .lower molecular weight alcohols require higher temperatures, than the higher molecular weight alcohols.

It has'also been found that the addition of a amount of promoter used may vary from about 5 to 15% by weight of oxygenated hydrocarbon feed, although higher proportions can be used.

As indicated in the'table presented below, a.

number of these alcohols were reacted with isobutane in the presence of sulphuric acid having a concentration of 98% :804. The reaction was carried out at the temperature indicated, obtaining the indicated yield of product.

The general procedure followed-in makingthese experiments involved charging the acid and isobutane to a reaction bomb provided with means for-maintaining the contents at a desired temperature. While subjecting the contents to stirrmg the alcohol was introduced at the'rate of about 100 cubic centimeters per hour. After the d amount of alcohol had been.- added agitation was continued for about minutes. The reaction product, after removal of the used acid, was transferred to. a stabilizer or distilling column. The temperature at the top of the column .was maintained at about 41 F., while the temsmall amoimt of a material, such as butylenes or large number of instances where elevated tem- 5 peratures would otherwise be required. In some instances the presence of a promoter is quite essential in order for thereaction to proceed. The

' perature at the bottom was maintained at 120 F.

inorder to remove the gaseous constituents.

The stabilized product wasthen withdrawn.

Alcohol gp py 50 e resence o a p h g kl H0 132. 3 117. 6 Normal butyL--. 50 Nil Nil. Normal butyl in the presence of a promotm' 135 126. 4 112. 0 lso 1.. 50 56. 8 hit it; T N li afamy 140 131. 3 I19. 3 Ian amyl...-- Nil Do 13) 152. 4 140. 0 Secondary hutyl carbino 158. 3 144. 0 mo e" a a: D 1 0 T amy v 70 167. 8 144. 0 Norm 70 Ni] Do in: 113.6 99. 6 Do 140 118. 6 104. 6 Methyl isopmpyl carbinol... 16 mo 121.9 acthyl hexanol 102 161. a, 129. 2 ychhexauoL 100 106. o

10% triisobutylene by weight of the 8100110]. 10% diisobuty one by weight of the alcohol.

The corresponding ethers can also be alkylated with isobutane, obtaining satisfactory yields. For

example, isopropyl ether was reacted with isobutane in the presence of 10% triisobutylene by weight of the ether, at a temperature of around F. From a charge mixture containing 80 the presence of in mum mum Mire for the ordinary atmospheric temperature alk'yl ntion of isopersilins with oleflns.

ERNEST I. rm LOUIS A. CLAIRE. 6mm! 3. HA'IUH. FRANK H. BRUNIR. 

